The drain plug is 16mm. When I was working, I was amazes at the GORILLAS that tighten this plug. It has an O ring gasket that doesn't need King Kong to tighten it. I put the Fomuto on my Georgetown and a 3/8 hose fits over the nipple and drain it into a Kitty Litter container( we have 3 cats). They hold 2 gallon, which is plenty. After the oil is drained, get an awl and punch a hole in the bottom of the filter. Loosen it up slightly before you punch it. Let it drain into the container, then get a few Walmart bags to catch the filter in, and your done.